Although the risks of continued opioid use following inpatient total joint arthroplasty (TJA) have been well-studied, these risks in the outpatient setting are not well known. The purpose of the present study was to characterize opioid use following outpatient compared with inpatient TJA.
In this retrospective cohort study, opioid-naïve patients who underwent inpatient or outpatient (no overnight stay) primary, elective TJA from 2007 to 2017 were identified within a large national commercial-claims insurance database. For inclusion in the study, patients had to have been continuously enrolled in the database for ≥12 months prior to and ≥6 months after the TJA procedure. Multivariable analyses controlling for demographics, geography, procedure, year, and comorbidities were utilized to determine the association between surgical setting and risk of persistent opioid use, defined as the patient still filling new opioid prescriptions >90 days postoperatively.
We identified a total of 92,506 opioid-naïve TJA patients, of whom 57,183 (61.8%) underwent total knee arthroplasty (TKA). Overall, 7,342 patients (7.9%) underwent an outpatient TJA procedure, including 4,194 outpatient TKAs. Outpatient TJA was associated with reduced surgical opioid prescribing (78.9% compared with 87.6% for inpatient procedures; p < 0.001). Among the 80,393 patients (86.9%) who received surgical opioids, the total amount of opioids prescribed (in morphine milligram equivalents) was similar between inpatient (median, 750; interquartile range, 450 to 1,200) and outpatient procedures (median, 750; interquartile range, 450 to 1,140; p = 0.47); however, inpatient TJA patients were significantly more likely to still be taking opioids after 90 days postoperatively (11.4% compared with 9.0% for outpatient procedures; p < 0.001). These results persisted in adjusted analysis (adjusted odds ratio, 1.13; 95% confidence interval, 1.03 to 1.24; p = 0.01).
Outpatient TJA patients who received opioid prescriptions were prescribed a similar amount of opioids as those undergoing inpatient TJA procedures, but were significantly less likely to become persistent opioid users, even when controlling for patient factors. Outpatient TJA, as compared with inpatient TJA, does not appear to be a risk factor for new opioid dependence, and these findings support the continued transition to the outpatient-TJA model for lower-risk patients.
Level of Evidence:
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.